Musical instrument pickups generate small electric signals corresponding to a frequency or frequencies of a note or notes being played. These electrical signals are created by one or more strings vibrating through a magnetic field. Musical instrument pickups, which are used for instruments such as a guitar, mandolin, bass, etc., fall into two general types, a single coil pickup and a double coil (i.e., humbucker) pickup.
The two types of musical instrument pickups work in different ways and each has its own characteristic sound. A conventional single coil pickup is composed of a plurality of magnets (e.g., one for each string) surrounded by copper wire. The single coil pickup has a characteristic sound having low notes that sound very clear and “twangy”, while the high notes can sound quite shrill and piercing. The single coil pickup is also sensitive to 60 cycle hum.
A conventional double coil pickup, as illustrated in FIG. 1, includes two coils 101/102 wired in series and out of phase with each other. The conventional double coil pickup consists of a plurality of metal cylindrical elements (i.e. pole pieces) 105 and a plurality of metal screws 104. The plurality of pole pieces 105 and the plurality of metal screws 104 are not themselves magnetic. Rather, they conduct a magnetic field generated by a bar magnet 103 located under plastic bobbins that contain the cylinders and screws. The entire assembly is supported by a base plate 106. This pickup reduces 60 cycle hum and has a sound characterized by sweet, sonorous highs at the expense of indistinct, muddy sounding lows.